Method and apparatus for grouting



I April 9, 1940- J. P.- HARTMAN -METHQD AND APPARATUS FOR GROUTING Filedy 28, 1938 Patented Apr. 9, 1940 UNITED STATES PATENT OFFICE 2,196,211METHOD'YAND APPARATUS FOR GROUTING John P. Hartman, Fort Peck, Mont.Application May 28, 1938, Serial No. 210,782 7 Claims. (01. 61-36)(Granted under the act- 01' March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) This invention described hereinmay be manufactured and used by or for the Government for governmentalpurposes, without the payment to me of any royalty thereon.

This invention relates generally to groutin but more particularly to agrouting tool and the method of using the same. 1

One object of the invention is to provide a multiple jet grouting tooladapted to cut through the subsoil with a combined jetting and sawingaction.

Another object of the invention is to provide Another object of theinvention is to'provide a grouting tool which is of simple, economicaland durable construction, and one which may be easily operated andcleaned.

Another object of the invention is to provide a method for hydraulicallycutting away the subsoil with a sawing action and forming an imperviouscurtain in the out area.

A further object of the invention is to provide a method and means forproducing a uniform and continuous grouted volume in the localitydesired and one which will be impervious to the seepage of water.

The invention which forms the subject matter of this application relatesto a method and means of grouting gravels, sands, silts and mixturesthereof, in which the groutingsolution or suspension is introduced underpressure in amanner resulting in the flotation of the material beinggrouted immediately surrounding the grouting tool.

Certain types of soil are very difiicult to grout, although they arequite pervious for a flow of water. The difiiculty arises wheneverthemaximum dimension of the pores of the soilis less than the diameterof minimum dimension of the grout particles, as the grout particlescannot penetrate into the pores regardless of the applied pressureunless some action takes place to enlarge the pore openings. In manycases the enlargement of the pores to permit penetration of the groutproduces detrimental effects in the original structural conditions ofthe adjacent property. It is also practically impossible to control thevolume to be grouted. V

The flotation process of grouting enlarges the pore space temporarilywithin definite controllable limits until the grout can penetrate,

after which the setting soil particles trap the grout particles in thesoil pore spaces.

The improved method and apparatus for e1- fecting grouting operationsmay be utilized in the following forms of engineering work:

Grouting of foundations for all types of structures;

Grouting around caissons, cribbings and coffer dams;

Grouting of earth, dams, levees-and dikes; 10

Grouting cores in earth dams, levees and dikes constructed of gravel,sand, silt and mixtures thereof, parallel to the axis of the structuresafter the complete placement of earth fill;

Grouting of material where it is notnecessary '16 to grout large areas,but merely to form cut-01f curtains.

Referring more particularly to the accompanying drawing in whichcorresponding parts are indicated by similar reference characters:

Fig. 1 is a front elevation of the grouting saw;

Fig. 2 is a side centrally sectionized elevation of the grouting saw;

Fig. 3 represents a section taken on the line 3-3 of Fig. 2; I Fig. 4 isan enlarged top plan view of one of the nozzles, as illustrated in Fig.1;

Fig. 5 is an enlarged sectionizedv view of a nozzle, as shown in Fig. 2;

Fig. 6 is a side elevation of a tractor provided ,30 with areciprocating apparatusv for operating the saw.

The grouting device or saw consists of a pipe 10, composed of metal orother suitable material, pointed at one end and equipped with a series,of nozzles I I extending longitudinally in a straight line throughoutits length. The pipe may be circular in shape, although those havingoval or streamlined sections, as shown inFig. 3, are preferred. Thenozzles I I through which the grout is forced, as will be furtherdescribed, are formed with a hexagonal head I! adapted to fit a wrenchand a slightly tapered and externally threaded body portion I3 adaptedto fit threaded holes 1'4 in the pipe.

The nozzles are dimensioned so as to be interchangeable in order toexpedite replacement after excessive wear, and also by varying the sizeof their internal passage I 5, adjustments can be made to adapt theequipment to the type and volume 50 of the grouting material.

A smaller pipe I6 is welded or otherwise fastened to the main pipe 10throughout its length and diametrically opposite to the longitudinal rowof nozzles II. This small pipe 16 is for the u passage of water underpressure, and is used to jet the main grout pipe l0 into the material tobe grouted.

The grout consisting of bentonite or other suitable material is pumpedinto the main grout pipe l0 under pressure and is expelled therefromthrough the nozzles I I. By proper spacing of the nozzles and by usingsufiicient pressure on the grout, the material immediately in front ofthe nozzles and some of the material surrounding the grouting pipe isfloated, resulting in a uicksand condition.

By employing a mechanism for producing a reciprocating motion, and towhich the upper flange ll of the grouting pipe [0 may be attached, suchas the mechanism shown on the tractor illustrated in Fig. 6, it ispossible to move the grouting pipe or saw vertically as it progresseshorizontally through the material to be grouted' in the direction of thenozzlejets, the action being similar to that of sawing. As thehorizontal movement progresses, the sand behind the pipe being no longerfloated, settles, trapping the grout in the pores of the material. Thismethod of grouting forms definite grouted volumes the sizes of which arefunctions of the size grouting equipment and the pressures used.

In carrying out the method for grouting with the saw described above asuitable tractor mounted operating mechanism is provided. This mechanismcomprises a reciprocating supporting tube [8 slidably mounted in asupporting bracket i9 and connected by a link 28 to an oscillatingrocker arm 2!. The rocker arm 2! is pivotally mounted on a shaft 22which is in turn mounted in two supporting brackets 23, only one ofwhich, is shown. In the illustration shown in Fig. 6, it will be notedthat the rocker arm 2!, is provided with a slot 25 which slidablyreceives the rectangularly projecting pin 26 of the crank arm 21.

The crank arm 21 is connected to a rotating shaft 28 which is operatedthrough gears connected to the tractor motor and which are not shown inthe illustration. The motor is adapted to effect a reciprocating motionof supporting tube 18 which is imparted to the saw H] to which it isconnected through its lower flange 3i and flange ll of the grouting pipeor saw.

As the tractor moves along the surface of the terrain the pipe or saw itwhich has been sunk into the subsoil is given a reciprocating motion bythe mechanism described above, as bentonite or other suitable groutingmaterial is pumped through the flexible tube 29 and supporting tube 18into the interior of the grouting pipe or saw I0, and out through thenozzle l I as shown in Fig. 6. The pipe [3, which is attached to the sawi0 is connected to a water supply (not shown) through the flexible tube311. The pipe it is of great advantage in sinking the saw as describedabove.

Having described my invention, what I claim as new and wish to secure byLetters Patent is:

1. A grouting saw comprising an ejecting pipe for conveying groutingmaterial provided with a longitudinal row of ejector nozzles, and alongitudinally aligned pipe of smaller diameter for conveying water,arranged diagonally opposite said nozzles and terminating with an outletopening at the end of said ejecting pipe.

2; In a grouting apparatus the combination with an internally boredgrouting tool, means for imparting a vertical and a longitudinalmovement to the tool, a source of cementitious material in communicationwith the bore of the tool, and means for discharging the material fromthe bore in the form of a plurality of streams.

3. In a grouting apparatus the combination with an internally boredgrouting tool, means for imparting a vertical and a longitudinalmovement to the tool, a source of cementitious material in communicationwith the bore of the tool, and means including a series of alignedopenings for discharging the material from the bore in the form of aplurality of superimposed streams.

4. In a grouting apparatus the combination with an internally boredgrouting tool, means for imparting a vertical and a longitudinalmovement to the tool, a source of cementitious material in communicationwith the bore of the tool, and means in connection with the tool fordischarging said material from the bore in the direction of thelongitudinal movement of the tool and in the form of a plurality ofsuperimposed streams, said means including a series of vertically spacednozzles.

5. In a grouting apparatus the combination with a grouting toolincluding an ejector and an irrigating tube; 01" means for imparting avertical and a longitudinal movement to said tool, a source ofcementitious material in communication with said ejector tube, a sourceof water supply connected to said irrigating tube, means including aplurality of vertically spaced nozzles for discharging the material fromsaid ejector tube in the form of a plurality of parallel verticallyspaced streams and in the direction of the longitudinal movement of thetool, and means for directing a stream of water from the irrigating tubein the direction of its vertical movement.

6. A grouting process for forming a subsoil wall consisting in lineallydirecting a series of superimposed streams of cementitious materialthrough said subsoil, and simultaneously imparting a vertical movementto said streams.

7. A grouting process for forming a subsoil wall substantiallyimpervious to moisture consisting in irrigating the subsoil with adownwardly directed jet of water and at the same time lineally directinga series of superimposed streams of cementitiousimaterial through thesubsoil, while imparting a reciprocatory and a longitudinal movement tosaid streams.

JOHN P. HARTMAN.

